Canopy structure and a wind turbine

ABSTRACT

Provided is a canopy structure for a nacelle of a wind turbine, including at least one side and a plurality of standard panels which all have the same length and the same width, wherein the at least one side is at least partly formed from the plurality of standard panels, and wherein each standard panel includes a flange which runs only along one edge of the standard panel. Advantageously, the canopy structure including the standard panels is able to reduce the need of a high number of different canopy parts. The amount of different types of molds or tools for producing the standard panels is reduced which leads to a more cost-effective production of the canopy structure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to European application No. 18159737.8,having a filing date of Mar. 2, 2018, the entire contents of which arehereby incorporated by reference.

FIELD OF TECHNOLOGY

The following relates to a canopy structure for a nacelle of a windturbine and to a wind turbine comprising such a canopy structure.

BACKGROUND

As wind turbines get bigger and bigger, the size of the nacelleslikewise increases to accommodate the size increasing equipment likegenerator, gearbox, power electronics or the like. In particular, theweight follows along this trend. Nacelles are usually provided with anoutside cover, named as canopy structure, surrounding an interior of thenacelle, wherein the canopy structure is normally prepared fromcustom-made cover sheets or panels which are attached to a nacellesupport structure. As such, the cover sheets are usually notload-carrying but provide some structural stiffness to the nacellesupport structure. The canopy structure mainly serves the purpose ofshielding the interior of the nacelle from the outside environment.

However, due to the increasing size of the nacelles, either numerouscover sheets need to be prepared which are then placed individually onthe outside of the nacelle support structure. This however is very timeconsuming from a manufacture point of view. Alternatively, bigger coversheets can be made which however requires large storage facilitiesbefore assembly and may not be easy to transport. Either way, the panelsare often custom-made for each individual placement in the overallcanopy structure layout, which requires individual and labor-intensivepreparation procedures, e.g. different molds or cutting tools have to beused before a complete canopy structure is prepared.

EP 2 942 522 A1 describes a wind turbine power generating apparatuscomprising a nacelle including a plurality of unit panels and afastening bolt for connecting the plurality of unit panels with oneanother.

U.S. Pat. No. 9,677,543 B2 describes a structure for a nacelle coverconnection portion of a wind turbine generator including a lengthy firstangled member fixed to an inside surface of a nacelle cover and formingan upper end portion of a side wall panel and a lengthy second angledmember fixed to the inside surface and forming a lower end portion of aroof panel. An upper surface of the first angled member and a lowersurface of the second angled member are aligned with and fixed to eachother. A covering portion covering the upper end portion from theoutside of a nacelle is provided at a predetermined interval from thesame and integral with the lower end portion so as to protrude to theoutside of the nacelle cover farther than the lower end portion.

SUMMARY

An aspect relates to an improved canopy structure for a nacelle of awind turbine.

Accordingly, a canopy structure for a nacelle of a wind turbine isprovided. The canopy structure comprises at least one side and aplurality of standard panels which all have the same length and the samewidth, wherein the at least one side is at least partly formed from theplurality of standard panels, and wherein each standard panel comprisesa flange which runs only along one edge of the standard panel.

Advantageously, the canopy structure comprising the standard panels isable to reduce the need of a high number of different canopy parts. Theamount of different types of molds or tools for producing the standardpanels is reduced which leads to a more cost-effective production of thecanopy structure. Lowering of the number of parts simplifies thelogistics related to production, transport, storage and assembly. Simpleshaped parts like the standard panels and high numbers of identicalparts makes transportation more cost-effective. The standard panels cantherefore be used to produce canopy structures for a variety ofdifferent wind turbine models.

The canopy structure is a nacelle cover or can be named as nacellecover. Apart from the standard panels, the canopy structure comprises aplurality of custom-made panels. The custom-made panels can comprisebottom panels corner panels and/or topside panels. All panels areattached to each other to form a self-carrying canopy structure.“Self-carrying” in this case means that the panels itself form aload-carrying structure that does not require a heavy metal frame towhich the panels are attached. “Standard” or “standardized” in thisrespect means that all the standard panels have the samethree-dimensional geometry, the same dimensions and are made of the samematerial. In particular, all standard panels are made with the same moldor tool. The standard panels can be made of metal or a compositematerial. A “plurality” means at least two standard panels. There aremore than two standard panels.

The canopy structure comprises a left side, a right side and a backendside. Further, the canopy structure can comprise a front side which isopen, a bottom and a topside. A hub of a rotor of the wind turbine isarranged at the front side. The standard panels can also used to producethe bottom and/or the topside of the canopy structure. The standardpanel is rectangular, wherein the length of the standard panel is largerthan the width. A “flange” is a section of the standard panel that isbent outwards from a basic section thereof. The basic section can be ametal or composite material sheet. The flange running along “only” or“solely” one edge means that the standard panel has a plurality ofedges, in particular four, wherein just one of the edges has a flangeand the other, in particular three, edges do not have such a flange. Thestandard panels can be provided with a conductive film layer which isthen connected by appropriate means to one another as to create aFaraday cage of the canopy structure for lightning protection.

According to an embodiment, the flange of the standard panel overlaps aneighbored standard panel. In the overlapping section, the standardpanels can be bolted and/or glued together.

According to a further embodiment, the flange is bent outwards from abasic section of the standard panel. In particular, the flange is bentperpendicular to the basic section. “Perpendicular” in this case meansan angle of 90°±10°, more of 90°±5°, more of 90°±1° and more of exactly90°.

According to a further embodiment, the flange is bent S-shaped, Z-shapedor L-shaped. “S-shaped” or “Z-shaped” means that the flange has a firstsection that is bent perpendicular to the basic section and a secondsection that is bent perpendicular to the first section. “L-shaped”means that the flange is bent perpendicular to the basic section.

According to a further embodiment, the standard panel comprises fouredges, wherein three edges of the standard panel are flange-free.“Flange-free” or “flange-less” edges do not have a flange. The standardpanel has a first edge, a second edge, a third edge and a fourth edge.The first edge and the third edge run along a length direction of thestandard panel. The second edge and the fourth edge run along a widthdirection of the standard panel. In particular, the first edge runsparallel to the third edge and the second edge runs parallel to thefourth edge. The first edge can be named as first lengthwise edge. Thesecond edge can be named as first widthwise edge. The third edge can benamed as second lengthwise edge. The fourth edge can be named as secondwidthwise edge.

According to a further embodiment, the flange runs only along alengthwise edge of the standard panel. In particular, the flange runsonly along the first lengthwise edge.

According to a further embodiment, the standard panel is curved.Alternatively, the standard panel is straight. Seen from an interior ofthe canopy structure, the standard panel can be curved outwards(concave) or inwards (convex). When being curved outwards, a space ofthe interior of the canopy structure is increased.

According to a further embodiment, the standard panel comprises astiffening rib which runs along a length direction of the standardpanel. The rib can either extend outwards or inwards towards theinterior of the canopy structure. The rib can be build up as a sandwichconstruction including fiber materials and foam core materials as partof a panel mold. This will allow the rib to be introduced and producedin the same process of producing the standard panel. This can be namedas “one shot solution”. The rib can alternatively be build up in an opencomposite box beam construction and can in turn be attached to analready prepared standard panel.

According to a further embodiment, the canopy structure has a sidelength, wherein a connected length of the standard panels when beingconnected to each other makes up at least 60%, more at least 70%, moreat least 80% and more at least 90% of the side length. The standardpanels together with the custom-made panels make up 100% of the sidelength.

According to a further embodiment, the width is less than 6 meters, moreless than 4 meters, more at least 1 meter and more at least 50centimeters. This enables an easy transport and handling of the standardpanels.

According to a further embodiment, the length is more than 3 meters,more than 5 meters and more than 8 meters. This enables the constructionof even very large-sized canopy structures.

According to a further embodiment, the canopy structure furthercomprises a nacelle skeleton to which the standard panels are attached.The nacelle skeleton connects the standard panels to a nacelle supportframe.

According to a further embodiment, the nacelle skeleton comprises atleast one interior support beam to which the standard panels areattached. The interior support beam runs parallel to the nacelle supportframe. The standard panels are attached to the interior support beam bymeans of brackets. The standard panels can be arranged vertical, thatmeans perpendicular to the interior support beam, or horizontal, thatmeans parallel to the interior support beam.

According to a further embodiment, the nacelle skeleton comprises aplurality of posts to which the at least one interior support beam isattached, wherein the posts are connected to a nacelle support frame ofthe nacelle. There can be provided four or more than four posts. Theposts can be placed at corners of the nacelle support frame or betweenthe corners. The posts can be straight. Alternatively, the posts canalso be bent outwards. The nacelle support frame can be in the form of arectangular and/or round shaped bedframe, wherein three interior supportbeams (separate or combined into one single piece) are connected to orrest on the posts.

Additionally, a wind turbine, comprising a nacelle and such a canopystructure is provided. The canopy structure is part of the nacelle.Apart from the canopy structure, the nacelle can comprise the nacellesupport frame to which the canopy structure is attached and a generator,a gearbox, electronic devices or the like which are arranged inside thecanopy structure. The nacelle is fixed to a tower of the wind turbine.“Wind turbine” presently refers to an apparatus converting the wind'skinetic energy into rotational energy, which may again be converted toelectrical energy by the apparatus.

Further possible implementations or alternative solutions of embodimentsof the invention also encompass combinations—that are not explicitlymentioned herein—of features described above or below with regard to theembodiments. The person skilled in the art may also add individual orisolated aspects and features to the most basic form of embodiments ofthe invention.

BRIEF DESCRIPTION

Some of the embodiments will be described in detail, with references tothe following Figures, wherein like designations denote like members,wherein:

FIG. 1 shows a perspective view of a wind turbine according to oneembodiment;

FIG. 2 shows a perspective view of a wind turbine rotor blade accordingto one embodiment;

FIG. 3 shows a perspective view of a canopy structure according to oneembodiment;

FIG. 4 shows a perspective exploded view of the canopy structureaccording to FIG. 3;

FIG. 5 shows different views of a standard panel according to oneembodiment;

FIG. 6 shows a view of a plurality of standard panels according to FIG.5;

FIG. 7 shows a cross-sectional view according to intersection lineVII-VII in FIG. 6;

FIG. 8 shows a further cross-sectional view according to intersectionline VII-VII in FIG. 6;

FIG. 9 shows a perspective view of a standard panel according to oneembodiment;

FIG. 10 shows a perspective exploded view of a nacelle according to oneembodiment;

FIG. 11 shows a perspective view of a canopy structure according to oneembodiment;

FIG. 12 shows an enlarged view of the canopy structure according to FIG.11;

FIG. 13 shows a perspective view of a canopy structure according to oneembodiment; and

FIG. 14 shows a perspective view of a canopy structure according to oneembodiment.

DETAILED DESCRIPTION

In the Figures, like reference numerals designate like or functionallyequivalent elements, unless otherwise indicated.

FIG. 1 shows a wind turbine 1 according to one embodiment.

The wind turbine 1 comprises a rotor 2 connected to a generator (notshown) arranged inside a nacelle 3. The nacelle 3 is arranged at theupper end of a tower 4 of the wind turbine 1.

The rotor 2 comprises three rotor blades 5. The rotor blades 5 areconnected to a hub 6 of the wind turbine 1. Rotors 2 of this kind mayhave diameters ranging from, for example, 30 to 160 meters or even more.The rotor blades 5 are subjected to high wind loads. At the same time,the rotor blades 5 need to be lightweight. For these reasons, rotorblades 5 in modern wind turbines 1 are manufactured fromfiber-reinforced composite materials. Therein, glass fibers aregenerally preferred over carbon fibers for cost reasons. Oftentimes,glass fibers in the form of unidirectional fiber mats are used.

FIG. 2 shows a rotor blade 5 according to one embodiment.

The rotor blade 5 comprises an aerodynamically designed portion 7, whichis shaped for optimum exploitation of the wind energy and a blade root 8for connecting the rotor blade 5 to the hub 6.

FIG. 3 shows a perspective view of one embodiment of a canopy structure9 for the nacelle 3. FIG. 4 shows an exploded view of the canopystructure 9.

The canopy structure 9 has a front side FS, where the hub 6 is arranged,a backend side BS, which faces away from the hub 6, a left side LS (seenfrom within the canopy structure 9 in direction of the hub 6) and aright side RS (seen from within the canopy structure 9 in direction ofthe hub 6). The canopy structure 9 is part of the nacelle 3. Apart fromthe canopy structure 9, the nacelle 3 can comprise a generator and/or agearbox which is arranged inside the canopy structure 9.

The canopy structure 9 comprises a plurality of panels 10 to 27. Thepanels 10 to 27 can be made of a fiber reinforced plastic or a metalsheet. The panels 10 to 27 are of different size and shape. Inparticular, the panels 10 to 27 can be custom-made. For example, thepanels 13 to 16 can form corners of the canopy structure 9, the panels10 to 12 can form a bottom of the canopy structure 9, whereas the panels17 to 27 can form a topside of the canopy structure 9. The panels 13 to16 can be named as “corner panels”. The panels 17 to 27 can be named as“topside panels”. The panels 10 to 12 can be named as “bottom panels”.

Apart from the panels 10 to 27 is provided a plurality of standardpanels 28 of which only three have a reference sign in FIG. 3 and FIG.4. “Standard” in this case means that all the standard panels 28 havethe same size and shape. In FIG. 3, the standard panels 28 are used toconstitute most of the left side LS, the right side RS and the backendside BS of the canopy structure 9. However, the standard panels 28 canbe used to constitute other parts of the canopy structure 9. Thestandard panels 28 can be connected to the panels 10 to 27. In FIG. 3and FIG. 4 the backend side BS, the left side LS and the right side RSeach comprise four standard panels 28.

Each standard panel 28 is strengthened as to provide stiffness to thestandard panels 28 so that they are load-carrying structures on theirown. Optionally the corner panels 13 to 16 can also be identical yetdifferent from the standard panels 28, at least in pairs of two (backendcorner panels 13, 16 and/or frontend corner panels 14, 15). However, asoutlets from the canopy structure 9 may be placed in these corner panels13 to 16 and/or because their shape makes them different from one sideopposite the other side, they are typically casted individually.

Most of the topside panels 17 to 27 to may also be identical to thestandard panels 28, but as hatches or other openings are typicallyplaced on top of the canopy structure 9, they may also be castedindividually. In addition, a length L (FIG. 5) of the standard panels 28when placed on the backend side BS, the left side LS and/or the rightside RS may provide a certain height H of the canopy structure 9 that ischosen to be different from a required width of the canopy structure 9.Accordingly, a length of these standardized topside panels 17 to 27 maybe of different dimension. Nonetheless, the top panels 17 to 27 maytherefore represent a second set of standard panels, being independentof the standard panels 28.

Similar, the bottom panels 10 to 12 are typically different from thestandard panels 28 as they have to be placed at least in part around thetower 4 carrying the nacelle 3 and thus need also to be castedindividually. Likewise, the frontend corner panels 14, 15 are differentdue to the hub 6 with the rotor 2 being attached to the nacelle 3.

FIG. 5 shows (from left to right) a perspective view, a side view and afront view of a standard panel 28.

The standard panels 28 are all concave in shape (extending outwards whenseen from an interior of the canopy structure 9). They may however alsoextend inwards. However, the outward concavity provides additionalvolume to the overall interior space available in the canopy structure9. Regardless of shape, the standard panels 28 are connected to oneanother so that they provide an essentially closed structure thatprotects the interior of the canopy structure 9 from an outsideenvironment.

To achieve this, the standard panels 28 may be glued or bolted together.Optionally, there can be a sealing in between joints of the standardpanels 28. The standard panels 28 can be detachably attached to oneanother for individual service/replacement purposes. In turn, allopenings of the complete canopy structure 9 (e.g. doors/hatches whenclosed) and interfaces towards rotor 2 and tower 4 are also sealed sothat the interior of the canopy structure 9 is (more or less) completelysealed from the outside environment. Thus, at an interface between givenstandard panels 28 and a relatively moving part considering the canopystructure 9 as a static structure, such interface comprises a flexiblesealing.

The number of standard panels 28 on each side RS, LS, BS depends on thedesired dimensions of the canopy structure 9 and a width W of thestandard panels 28. In addition, the number of standard panels 28 on theright side RS and the left side LS may be different from the number ofstandard panels 28 at the backend side BS. Nonetheless, for a given sidelength SL (FIG. 3) of the canopy structure 9, a connected length CL(FIG. 3) of the standard panels 28 (when being connected to one another)makes up at least 70% of the side length SL and more more than 80% ofthe side length SL.

As can be seen in FIG. 5, each standard panel 28 comprises a basicsection 29 which is curved and at least one flange 30 which facesinwards. The flange 30 serves two purposes, namely to act as a stiffenere.g. for wind loads or in support of any load arising from placement ofstructures on top of the canopy structure 9 and optionally to act as asimple means of connecting the standard panels 28 to each other.

As FIG. 5 (right side) shows, the standard panel 28 has a first edge E1,a second edge E2, a third edge E3 and a fourth edge E4. The standardpanel is rectangular. The first edge E1 and the third edge E3 run alonga length direction LD of the standard panel 28. The length L is measuredin the length direction LD. The second edge E2 and the fourth edge E4run along a width direction WD of the standard panel 28. The width W ismeasured in the width direction WD. The first edge E1 runs parallel tothe third edge E3 and the second edge E2 runs parallel to the fourthedge E4. The first edge E1 can be named as first lengthwise edge. Thesecond edge E2 can be named as first widthwise edge. The third edge E3can be named as second lengthwise edge. The fourth edge E4 can be namedas second widthwise edge. As can be seen from FIG. 5, the flange 30 runssolely or only along the first lengthwise edge E1. Alternatively, theflange 30 can run along the second lengthwise edge E3. The flange 30 canalso run along one of the widthwise edges E2, E4.

FIG. 6 shows a view of a plurality of standard panels 28 overlappingeach other. FIG. 7 shows a sectional view according to intersection lineVII-VII. FIG. 8 shows a sectional view of an alternative embodiment ofthe standard panels 28.

The flanges 30 of the standard panels 28 comprise an S-shaped orZ-shaped bend (FIG. 7) at one end lengthwise the standard panel 28, sothat the standard panels 28 can overlap one another as illustrated inFIG. 6 and FIG. 7. In alternative embodiment (FIG. 8), the standardpanels 28 may have a simplified profile i.e. an L-shaped profile. Thestandard panels 28 may in addition be connected to one another at thisoverlapping section (e.g. bolted or glued together). In addition, theflanges 30 are bended (e.g. to 90°) at their ends as to allow attachmentof the standard panels 28 to a support beam/strut of a main nacellesupport, e.g. via a bracket connecting the two structures.

Any other panels 10 to 27 used to provide the full canopy structure 9may also comprise such a S-shaped flange 30 so that they too overlap andare able to “mate” with the standard panels 28. Since all the panels 10to 28 used to make a complete canopy structure 9 are attached to oneanother, the canopy structure 9 can in principle be directly attachedonly via the bottom panels 10 to 12 to a yaw arrangement (i.e. to a yawbearing) of the wind turbine 1 and thus be carried only via thisattachment point and follow a yaw movement of the wind turbine 1.

In accordance with the design of the standard panels 28 and theirability to function as load-carrying element, two, three, four or morestandard panels 28 are provided on each of the left side LS, right sideRS and backend side BS to provide sufficient strength and ability towithstand the foreseen loads to the canopy structure 9 and in particularloads arising from any structures/items placed on top of the canopystructure 9 (e.g. a helipad).

As mentioned before, at any given side LS, RS, BS of the canopystructure 9, the standard panels 28 are connected directly to oneanother and thus represent a continuous outer surface of the canopystructure 9. However, and in alternative, “non-standard” panels ofvarying width may be placed in between the standard panels 28 atdifferent sequence. This option provides a flexible solution to easilyadjust the side length SL for example.

The length L of the standard panels 28 can be chosen to meet therequirement of a given wind turbine model, but the standard panels 28are longer than 3 meters, more longer than 5 meters, and may even belonger than 8 meters to meet the requirements of very large wind turbinenacelles.

The width W of the standard panels 28 is likewise chosen to meet therequirement of a given wind turbine model. However, for ease ofhandling, the width W is less than 6 meters and less than 4 meters. Inorder for ease of installation (i.e. the more standard panels 28 thatwill make up a side LS, RS, BS, the more time consuming this task maybe), a minimum size of the width W is 50 cm or more at least 1 meter.

Nonetheless, the dimensions of the standard panels 28 are chosen so thatthey can be easily transported by road or railway e.g. to meet localmaximum size transport requirements and even so that the standard panels28 can be stored in standard sized containers, e.g. for sea transport.These size requirements are applicable to both stacks of multiplestandard panels 28 or individual standard panels 28 as well as to anyother of the panels 10 to 27 to make a complete canopy structure 9.

A thickness of the standard panels 28 depends on the material chosen andmay be constant over the entire standard panel 28 but can also varyacross the length direction LD and a spanwise direction (width directionWD). The standard panels 28 are provided in full length of the intendedheight H (FIG. 3) of the canopy structure 9, but individual panels canalso be casted as two or more pieces and preassembled before placement.Nonetheless, the standard panels 28 are made as “single pieces” in thesense that they are molded casted as a single piece structure includingbeing shaped from a single sheet of material e.g. a single plate of agiven material being shaped into the desired form and dimension.

Materials that are suitable for the panels 10 to 28 include fiberfabrics such as glass, aramid, carbon and natural fibers and/or resinsuch as polyesters, vinyl esters, or epoxies. Nonetheless, metalstandard panels 28 can also be used. The panels 10 to 28 can be providedwith a conductive film layer (integrated or placed on a surface) whichis then connected by appropriate means to one another as to create aFaraday cage of the nacelle 3 for lightning protection.

FIG. 9 shows a perspective view of an alternative embodiment of astandard panel 28.

In this embodiment of the standard panel 28, the stiffeningcharacteristic is not provided by a flange 30 but by a rib 31 placedwithin the basic section 29 or at a side of the basic section 29. Therib 31 can either extend outwards or inwards towards the interior of thecanopy structure 9. The rib 31 can be build up as a sandwichconstruction including fiber materials and foam core materials as partof a panel mold. This will allow the rib 31 to be introduced andproduced in the same process of producing the standard panel 28. Thiscan be named as “one shot solution”. The rib 31 can alternatively bebuilt up in an open composite box beam construction and can in turn beattached to an already prepared standard panel 28. Accordingly, the rib31 can be seen as an integrated part of the standard panel 28 (i.e. aone-piece panel) or as a separate piece attached to the standard panel28, wherein the rib 31 itself can be hollow on the inside or a solidstructure. Additionally, each standard panel 28 can have both, a flange30 and a rib 31.

FIG. 10 shows a perspective exploded view of the nacelle 3 including thecanopy structure 9.

The standard panels 28 can be at least be attached to an interiorsupport structure 32 that in turn is connected to a nacelle supportframe 33. The nacelle support frame 33 supports bearing housings, agenerator, a gearbox, power electronics, service access ways or thelike. This arrangement according to FIG. 10 may provide additionalsupport to the canopy structure 9 and makes placement of the standardpanels 28 during preassembly easier, especially if this interior supportstructure 32 is firmly attached to the nacelle support frame 33. Theinterior support structure 32 can have the form of a rectangular framemade of beams, e.g. aluminum, steel or fiber composite beams. Theinterior support structure 32 is part of the canopy structure 9.

FIG. 11 and FIG. 12 both show partial views of the canopy structure 9.

The interior support structure 32 can comprise at least one interiorsupport beam 34 which can be arranged horizontally. There can beprovided a plurality of interior support beams 34. The standard panels28 and the corner panels 13 to 16 are attached individually via brackets35 to one or more interior support beams 34. The interior support beam34 is placed in the interior of the canopy structure 9 along the sidesRS, LS, BS of the canopy structure 9. Said interior support beam 34 canoptionally be directly or indirectly connected to the nacelle supportframe 33.

As mentioned before, the standard panels 28 are of such a strength thatthey minimize the need for a compete nacelle skeleton as normally usedin known nacelle layouts to carry the canopy structure 9. In thisrespect, such skeleton may be seen as being integrated into the standardpanels 28 and optionally also the corner panels 13 to 16.

FIG. 13 and FIG. 14 show perspective views of two different embodimentsof the canopy structure 9.

As can be seen from FIG. 13, the interior support beam 34 is connectedto the nacelle support frame 33 by means of posts 36 to 39. There can beprovided four or more than four posts 36 to 39. The posts 36 to 39 canbe placed at corners of the nacelle support frame 33 or between thecorners. The posts 36 to 39 can be straight. As can be seen from FIG.14, the posts 36 to 39 can also be bent outwards. The nacelle supportframe 33 can be in the form of a rectangular and/or round shapedbedframe, wherein three interior support beams 34 (separate or combinedinto one single piece) are connected to or rest on the posts 36 to 39.The posts 36 to 39 together with the interior support beam 34constitutes an optimized nacelle skeleton 40. “Optimized” in this casemeans that the nacelle skeleton 40 has less parts and is much lighterthat known nacelle skeletons in form of a metal cage or frame. Thenacelle skeleton 40 can comprise the interior support structure 32.

In another alternative embodiment, the standard panels 28 can bepositioned in a horizontal direction (opposed to vertical direction aspreviously described). A combination of the two ways may also beapplicable, i.e. left side LS and right side RS in one direction (e.g.vertical) and backend side BS in other direction (i.e. horizontal).

In the afore-mentioned case, the nacelle skeleton 40 also needs to beadapted to this horizontal placement of the standard panels 28. However,the nacelle skeleton 40 could in principle be a set of posts 36 to 39 asshown in FIG. 13 for example, wherein the standard panels 28individually are attached directly, or indirectly via a connection to acorner panel 13 to 16 which in turn is attached to a post 36 to 39.

In summary, the canopy structure 9 comprising the standard panels 28 isable to reduce the need of a high number of different canopy parts andhas the following advantages. The amount of different types of molds ortools is reduced which leads to a more cost-effective production of thecanopy structure 9. Lowering of the number of parts simplifies thelogistics related to production, transport, storage and assembly. Simpleshaped parts like the standard panels 28 and high numbers of identicalparts makes transportation more cost-effective. Higher volumes of thesame parts allow higher level of production giving better end-qualityand price. One type of standard panel 28 is used for both sides RS, LSand backend side BS of the canopy structure 9. Each standard panel 28includes the flange 30 facing inwards, serving two purposes, namely toact as a stiffener e.g. for wind and weight loads and to act as a simpleconnection (canopy connection) to a main nacelle structure, e.g. to thenacelle support frame 33. The standard panel 28 allows a simple paneldesign with non-complex attachment points to the main structure of thenacelle 3.

Further, an assembly of preassemblies (i.e. left side LS, right side RSand backend side BS) is made possible using only one type of standardpanel 28. Preassembly can be done by using glue or bolts or both. Thedesign concept is based on a self-carrying construction of the canopystructure 9 with point connections to the nacelle support frame 33. Thedesign concept does not rely on a complete, complex and heavy internalsteel frame construction to carry/support each individual panel 10 to28. All special functions (skylights, outlets e.g. drainage holes andlightning protection receivers, etc.) are placed in custom made panelssuch as corner panels 13 to 16, bottom panels 10 to 12 or topside panels17 to 27. In alternative, these functionalities can be placed andfunction via holes drilled, cut or sawed into a standard panel 28.

In particular, the standard panels 28 are made of sufficient strengththat they provide support to the nacelle 3 and minimizes the need forheavy steel structures to carry loads from e.g. equipment placed on topof the nacelle 3 such as meteorological equipment, landing platforms(heli-pad, heli-hoist or helicopter platform) and/or intermediate partsto be transferred into the nacelle 3 or used for other parts of the windturbine 1. This is especially advantageous as it reduces, if not evenremoves, the need for a structural framework within the canopy structure9 normally comprising supporting diagonal and/or transverse struts.

Although the present invention has been disclosed in the form ofpreferred embodiments and variations thereon, it will be understood thatnumerous additional modifications and variations could be made theretowithout departing from the scope of the invention.

For the sake of clarity, it is to be understood that the use of ‘a’ or‘an’ throughout this application does not exclude a plurality, and‘comprising’ does not exclude other steps or elements.

The invention claimed is:
 1. A canopy structure for a nacelle of a windturbine, comprising: at least one side; and a plurality of standardpanels having a same length and a same width; wherein a portion of theat least one side formed from the plurality of standard panels, and eachstandard panel comprises a flange which runs only along one lengthwiseedge of the standard panel; wherein the flange extends vertically in alengthwise direction along the one lengthwise edge of the standardpanel; wherein a front face of the flange is offset from a front face ofthe standard panel to mate with a portion of a rear face of aneighboring standard panel.
 2. The canopy structure according to claim1, wherein the flange of the standard panel overlaps the neighboringstandard panel.
 3. The canopy structure according to claim 1, whereinthe flange is bent outwards from a basic section of the standard panel.4. The canopy structure according to according to claim 1, wherein theflange is bent S-shaped, Z-shaped, or L-shaped.
 5. The canopy structureaccording to claim 1, wherein the standard panel comprises four edges,and wherein three edges of the standard panel are flange-free.
 6. Thecanopy structure according to claim 1, wherein the standard panel iscurved.
 7. The canopy structure according to claim 1, wherein thestandard panel comprises a stiffening rib which runs along a lengthdirection of the standard panel.
 8. The canopy structure according toclaim 1, wherein the canopy structure has a side length, and wherein aconnected length of the standard panels when being connected to eachother makes up at least 60% of the side length.
 9. The canopy structureaccording to claim 1, wherein the width is less than 6 meters, and atleast 1 meter.
 10. The canopy structure according to claim 1, whereinthe length is more than 3 meters.
 11. The canopy structure according toclaim 1, further comprising a nacelle skeleton to which the plurality ofstandard panels are attached.
 12. The canopy structure according toclaim 11, wherein the nacelle skeleton comprises at least one interiorsupport beam to which the plurality of standard panels are attached. 13.The canopy structure according to claim 12, wherein the nacelle skeletoncomprises a plurality of posts to which the at least one interiorsupport beam is attached, and wherein the plurality of posts areconnected to a nacelle support frame of the nacelle.
 14. A wind turbinecomprising a nacelle and the canopy structure according to claim 1.